From 52616a4994aa480a9623a11b9f556bcd0ec73a3e Mon Sep 17 00:00:00 2001
From: Kovid Goyal <kovid@kovidgoyal.net>
Date: Mon, 5 May 2025 13:36:37 +0530
Subject: [PATCH] News download: Fix Next/Previous links not working when the
 pointed to article failed to download

---
 src/calibre/web/feeds/news.py      | 29 ++++++++++++++++++++++-------
 src/calibre/web/feeds/templates.py |  8 ++++----
 2 files changed, 26 insertions(+), 11 deletions(-)

diff --git a/src/calibre/web/feeds/news.py b/src/calibre/web/feeds/news.py
index 563a70743c..32b4a7fa87 100644
--- a/src/calibre/web/feeds/news.py
+++ b/src/calibre/web/feeds/news.py
@@ -1863,13 +1863,28 @@ class BasicNewsRecipe(Recipe):
         return soup
 
     def internal_postprocess_book(self, oeb, opts, log):
-        if self.resolve_internal_links and self.article_url_map:
-            seen = set()
-            for item in oeb.spine:
-                for a in item.data.xpath('//*[local-name()="a" and @href]'):
-                    if a.get('rel') == 'calibre-downloaded-from':
-                        continue
-                    url = a.get('href')
+        seen = set()
+        for i, item in enumerate(oeb.spine):
+            for a in item.data.xpath('//*[local-name()="a" and @href]'):
+                if (rel := a.get('rel')) == 'calibre-downloaded-from':
+                    continue
+                url = a.get('href')
+                if not url:
+                    continue
+                if rel in ('articlenextlink', 'articleprevlink'):
+                    abshref = item.abshref(url)
+                    if abshref not in oeb.manifest.hrefs:
+                        if rel == 'articlenextlink':
+                            nextitem = oeb.spine[i + 1] if i + 1 < len(oeb.spine) else None
+                        else:
+                            nextitem = oeb.spine[i - 1] if i else None
+                        if nextitem is None:
+                            a.text = None
+                            a.attrib.pop('href')
+                        else:
+                            a.set('href', item.relhref(nextitem.href))
+                    continue
+                if self.resolve_internal_links and self.article_url_map:
                     for curl in self.canonicalize_internal_url(url):
                         articles = self.article_url_map.get(curl)
                         if articles:
diff --git a/src/calibre/web/feeds/templates.py b/src/calibre/web/feeds/templates.py
index cd354cc000..c75d93481c 100644
--- a/src/calibre/web/feeds/templates.py
+++ b/src/calibre/web/feeds/templates.py
@@ -225,7 +225,7 @@ class NavBarTemplate(Template):
             up = '../..' if art == number_of_articles_in_feed - 1 else '..'
             href = f'{prefix}{up}/{next_art}/index.html'
             navbar.text = '| '
-            navbar.append(A(_('Next'), href=href))
+            navbar.append(A(_('Next'), href=href, rel='articlenextlink'))
         href = f'{prefix}../index.html#article_{art}'
         next(navbar.iterchildren(reversed=True)).tail = ' | '
         navbar.append(A(_('Section menu'), href=href))
@@ -235,7 +235,7 @@ class NavBarTemplate(Template):
         if art > 0 and not bottom:
             href = f'{prefix}../article_{art - 1}/index.html'
             next(navbar.iterchildren(reversed=True)).tail = ' | '
-            navbar.append(A(_('Previous'), href=href))
+            navbar.append(A(_('Previous'), href=href, rel='articleprevlink'))
         next(navbar.iterchildren(reversed=True)).tail = ' | '
         if not bottom:
             navbar.append(HR())
@@ -402,7 +402,7 @@ class TouchscreenNavBarTemplate(Template):
             navbar.append(BR())
         # | Previous
         if art > 0:
-            link = A(attrs('article_link'),_('Previous'),href=f'{prefix}../article_{art - 1}/index.html')
+            link = A(attrs('article_link'),_('Previous'), rel='articleprevlink', href=f'{prefix}../article_{art - 1}/index.html')
             navbar_tr.append(TD(attrs('article_prev'),link))
         else:
             navbar_tr.append(TD(attrs('article_prev'),''))
@@ -419,7 +419,7 @@ class TouchscreenNavBarTemplate(Template):
                 else f'article_{art + 1}'
         up = '../..' if art == number_of_articles_in_feed - 1 else '..'
 
-        link = A(attrs('article_link'), _('Next'), href=f'{prefix}{up}/{next_art}/index.html')
+        link = A(attrs('article_link'), _('Next'), rel='articlenextlink', href=f'{prefix}{up}/{next_art}/index.html')
         navbar_tr.append(TD(attrs('article_next'),link))
         navbar_t.append(navbar_tr)
         navbar.append(navbar_t)